Display Standard Out (#127)

Attach a string builder as System.Console.Out and send its contents to the notebook on Display and when execution completes. Do not send a "pyout" message when the result of a cell is of type unit, in order to avoid printing "<null>".
fsprojects · Jan 19, 2017 · ee394e8 · ee394e8
1 parent 2e0bf6f
commit ee394e8
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Showing 3 changed files with 19 additions and 7 deletions.
diff --git a/src/IfSharp.Kernel/App.fs b/src/IfSharp.Kernel/App.fs
@@ -47,6 +47,10 @@ module App =
     let Display (value : obj) =
 
         if value <> null then
+            if sbPrint.Length > 0 then
+                Kernel.Value.SendDisplayData("text/plain", sbPrint.ToString())
+                sbPrint.Clear() |> ignore
+
             let printer = Printers.findDisplayPrinter(value.GetType())
             let (_, callback) = printer
             let callbackValue = callback(value)

diff --git a/src/IfSharp.Kernel/Evaluation.fs b/src/IfSharp.Kernel/Evaluation.fs
@@ -33,9 +33,11 @@ module Evaluation =
     let internal startSession () =
         let sbOut = new StringBuilder()
         let sbErr = new StringBuilder()
+        let sbPrint = new StringBuilder()
         let inStream = new StringReader("")
         let outStream = new StringWriter(sbOut)
         let errStream = new StringWriter(sbErr)
+        let printStream = new StringWriter(sbPrint)
 
         let fsiObj = Microsoft.FSharp.Compiler.Interactive.Settings.fsi
         let fsiConfig = FsiEvaluationSession.GetDefaultConfiguration(fsiObj, false)
@@ -54,10 +56,12 @@ module Evaluation =
         let extraPrinters = 
           unbox<ResizeArray<System.Type * (obj -> seq<string * string> * string)>>
             (fsiSession.EvalExpression("FsInteractiveService.htmlPrinters").Value.ReflectionValue)
-        sbErr, sbOut, extraPrinters, fsiSession
+
+        Console.SetOut(printStream)
+        sbErr, sbOut, sbPrint, extraPrinters, fsiSession
 
     let internal fsiout = ref false
-    let internal sbErr, sbOut, extraPrinters, fsiEval = startSession ()
+    let internal sbErr, sbOut, sbPrint, extraPrinters, fsiEval = startSession ()
 
     /// Gets `it` only if `it` was printed to the console
     let GetLastExpression() =

diff --git a/src/IfSharp.Kernel/Kernel.fs b/src/IfSharp.Kernel/Kernel.fs
@@ -303,6 +303,7 @@ type IfSharpKernel(connectionInformation : ConnectionInformation) =
         // clear some state
         sbOut.Clear() |> ignore
         sbErr.Clear() |> ignore
+        sbPrint.Clear() |> ignore
         payload.Clear()
 
         // only increment if we are not silent
@@ -323,6 +324,9 @@ type IfSharpKernel(connectionInformation : ConnectionInformation) =
                 handleException exn
                 Some exn
 
+        if sbPrint.Length > 0 then
+            sendDisplayData "text/plain" (sbPrint.ToString()) "display_data"
+
         if sbErr.Length > 0 then
             let err = sbErr.ToString().Trim()
             let executeReply =
@@ -353,11 +357,11 @@ type IfSharpKernel(connectionInformation : ConnectionInformation) =
                 let lastExpression = GetLastExpression()
                 match lastExpression with
                 | Some(it) -> 
-                        
-                    let printer = Printers.findDisplayPrinter(it.ReflectionType)
-                    let (_, callback) = printer
-                    let callbackValue = callback(it.ReflectionValue)
-                    sendDisplayData callbackValue.ContentType callbackValue.Data "pyout"
+                    if it.ReflectionType <> typeof<unit> then
+                        let printer = Printers.findDisplayPrinter(it.ReflectionType)
+                        let (_, callback) = printer
+                        let callbackValue = callback(it.ReflectionValue)
+                        sendDisplayData callbackValue.ContentType callbackValue.Data "pyout"
 
                 | None -> ()